124 TUFTS .COLLEGE STUDIES, VOL. II, No. 3 



smooth, projecting from the tube into the conjugating cells.* 

 N.J., Pa., Florida, Cal. 



5. M. MINNESOTENSIS Wolle, 1887, p. 228, PI. CXLVI, 

 fig. 3. Filaments 15-18 p. diam., cells 4-5 diam. long; spores 

 spherical, reddish brown, about 60 p. diam., projecting much 

 into the conjugating cells. Minn. 



6. M. DIVARICATA Wolle, 1887, p. 228, PI. CXLVI, fig. 4. 

 Filaments 20 ti diam., cells 4-10 diam. long, fertile cells some- 

 what geniculate ; spores about 45 p. diam., brown, projecting into 

 the conjugating cells. Pa. 



7. M. DELICATULA Wolle, 1887, p. 228, PI. CXLVI, fig. 5. 

 Filaments 12-14 M diam.. cells 4-6 diam. long; spores spherical, 

 25-30 /u, diam., .projecting slightly into the conjugating cells. 

 Canada. 



The four species last named have the character in common 

 of large spores occupying not only the whole length of the tube, 

 but also part of each of the conjugating cells. M. sphaerocarpa 

 has been found in California, agreeing well with Wolle's de- 

 scription and figure ; the three others are known only by Wolle's 

 descriptions ; if his figures are correct, it would seem difficult to 

 place them under species before described, and they differ 

 too much to be consolidated in one species ; there seems 

 to be no better way than to copy the descriptions and await 

 developments. 



8. M. VERRUCOSA Wolle, 1887, p. 229, PI. CXLVIII, fig. 5. 

 Filaments 13-14 p- diam., cells 6-10 diam. long, somewhat genic- 

 ulate ; spores transversely ovoid, projecting into the conjugating 

 cells, about 40X20-25 /A; membrane brown, coarsely granular. 

 Alabama. 



An imperfectly known plant, no sterile filaments having been 

 recorded ; but the characters seem to make it a distinct species ; 

 unless indeed it might be an ill-preserved and . inaccurately 

 figured Debarya glyptosperma. 



9. M. ROBUSTA (De Bary) Wittrock in Wittr. & Nordst., 

 Alg. Exsicc., No. 651 ; Mesocarpus robustus De Bary, 1858, p. 

 80, PI. II, fig. 16; Wolle, 1887, p. 231, PI. CXLVII, fig. 5. 



* M. levis (Kiitz.) Archer, 1867, PI. VIII, figs. 1-3, is near M. sphacro- 

 carpa, but has shorter cells and spores of about the same diameter as the 

 filaments, but considerably longer, and set at right angles to the fila- 

 ments. There is a somewhat doubtful report of its occurrence in the 

 West Indies. 



